IGHE and hypersensitivity reaction disease: The following allergic reactions were identified in the 2001 position paper of the European Academy of Allergology and Clinical Immunology (EAACI): IgE-mediated (type I reactions in the Gells–Coombs classification of hypersensitivity reactions) and non-IgE-mediated (type II–IV reactions in the Gells–Coombs classification and other reactions that activate immune mechanisms) [3].